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In my GIS department, we purchase vector GIS data and regular updates. Each update delivery includes a new "snapshot" of the dataset, which is a brand new version of the entire dataset. As you can imagine, we need to analyze the differences between consecutive versions, that is the lists of features that have been inserted, deleted, or changed (geometry and/or attributes). The dataset structure does not change from a version to another (feature types, attributes names and types, geometry types, etc.).

I started developing my own tool, GeoDiff, to analyze these differences.

Is there any existing practice, standard, or tool to do this?

I guess it is quite a common problem, which should have solutions!

PolyGeo
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julien
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    As you anyhow pay for it: did you ask the provider of the data if they could already pre-process these changes? – Babel Dec 24 '20 at 18:19
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    You can have a look at this answer: https://gis.stackexchange.com/a/372415/63384 – ahmadhanb Dec 24 '20 at 22:05
  • @babel: indeed, that is why I would like to learn about existing practices to represent the differences (formats) and tools to use these differences on our business data. – julien Dec 24 '20 at 22:47
  • @ahmadhanb Thanks. Very interesting indeed ! – julien Dec 24 '20 at 22:53

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You don't say what GIS software your department uses, so I'll respond with answers for both QGIS and ArcMap.

QGIS at 3.16.1 has a tool, Detect Dataset Changes, which I have use with great success. This tool identifies differences in both geometry and attributes. I appreciate that it outputs new layers which visually show both geometry and attribute changes.

ArcMap at 10.8.1 has the tools Feature Compare and Table Compare. I don't have any personal experience with them, but I conducted a quick and simple test this morning and they seemed to work just fine.

PolyGeo
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Stu Smith
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